Not sure if you are still messing with this, but here is a write up I did on one that I opened a while back. This is my go to method on Sentrys. Hope something helps.

hawk-lock wrote:Hey all. I am new to the forums and have been browsing for a few days. I have picked up a lot of good info and have enjoyed reading about several topics. I thought I would give back and post a few things that I learned while working on this safe.

I was given a small Sentry fire safe a few weeks ago and had played with it a little, but didn't give it a serious run until yesterday. It is a combination safe with a tubular key lock. The tubular lock is not an override, but must be solved in addition to the combination. It is direct entry with three wheels. The fence would ride on wheels 1 and 2 and then there were false gates on wheel three (11 false, one real). I tried several times to map wheels 1 & 2 looking for possible gates, but never really found anything on this safe that jumped out. I tried pointers attached to the handle and then did the laser pointer thing (which is a GREAT idea). I think one thing that made the pointer setup difficult on this safe was that the handle is plastic and had some give to it. It was difficult to apply pressure to the handle without over-pressuring it and bending the handle which throws the readings off. After several hours of messing around, I had only come up with one number that showed any promise (and it didn't end up being a gate). I also checked the width of the false gates looking for a noticeable difference in size, but did not find anything.

I was starting to get frustrated (and kept thinking about the wonderful assortment of cut-off tools that were at my disposal), but went back and thought over my processes. Here is what I ended up doing. The third wheel really didn't matter since it was lower than the other two. It will be the last wheel solved and will be easy to solve once the other two gates are found. I would know when the fence is dropping into the first two gates, because the dial would bind when the fence dropped onto the false gates of wheel three. I also assumed from reading other posts that I probably was dealing with gates that were about 3 increments wide. With that in mind I decided to park wheel 1 (I started at 39) and then dial wheel 2 around in 2.5 increments checking to see if I happened to have the gates aligned (each time you check, you have to make sure that wheel three is positioned at a false gate). Once I worked my way around wheel 2 and failed, I went back and adjusted wheel 1 by three increments and then started dialing wheel 2 again. I got real lucky because wheel 1 was 42, so I hit it on the second series. When wheel 2 came around to 20, I could feel the fence drop onto the false gate. At this point it is just a matter of running around the 12 false gates and checking to see which one is real.

The other thing that you have to deal with is the tubular lock. I did not have a key, so I just pulled the lock out. I picked up a tip from another topic on the forum that there is a metal clip just under the plastic face on the door. If you pry the plastic up, you can reach under and pull the clip off and the lock slips out. There is a relocking device that you can push out of the way through that same hole after you solve the combination. I have picked and decoded my lock and will make a new key with my Blitz and tubular adapter.

The safe did have contents in it. That is always exciting. However, I got this safe from a local nursing home that I work for. It had been collecting dust in the corner of a maintenance shed for several years. Most of the contents were not real significant, but there were a couple of rings and an old family photo that I feel need to be returned to the families. Maybe I'll get some good press out of it - but more importantly, I'll be able to sleep at night!

I hope this helps someone out. I will try to post a picture when I figure out how to do that!